A liquid crystal display device is composed mainly of a display panel and a backlight source. The display panel is usually provided above the backlight source. There are two common types for arranging a light source in the backlight source, that is, direct-light-type and side-light-type.
A direct-light-type backlight source is illustrated in FIG. 1. A light source 2 is provided on a backplate 1, and the light emitted from the light source 2 directly shines on the display panel 6 above the backlight source. Commonly, a diffuser plate 3 is provided between the light source 2 of the backlight source and the display panel 6 and used to blend and diffuse the light emitted from the light source 2, so that the light emitted from the light source 2 shines on the display panel 6 more evenly. Presently, as to the direct-light-type backlight source in a large-sized display panel, due to the large size, after the display panel 6 is provided above the backlight source, the central region of the display panel 6 can sink under the action of its gravity, this causes a curvature with higher periphery and lower center and thus influences the picture display quality.
Conventional solution is to provide a support between the backplate and the diffuser plate, but the support needs drilling into the backplate and being fixed using a fastener or a screw, and this depresses the assembly efficiency of the backlight source greatly. Further, a contact shade can occur at the location where the support contacts with the diffuser plate, and thus affects the picture display quality.